GEOL 1 CHAPTER 4

• -EXPLORATORY PIT- AN EXCAVATION LARGE ENOUGH FOR A PERSON TO OBSERVE AND SAMPLE COMFORTABLY
• HAND-AUGER BORING - AUGERS ROTATED AND WITHDRAWN CAREFULLY FOR REMOVAL OF SOIL
• • SAMPLING- A MATTER THAT DOES NOT ALWAYS RECEIVE THE ATTENTION IT DESERVES
• • PITS- CAN USUALLY BE DUG, LOGGED, AND FILLED AT A RATE ABOUT 8-12 A DAY
• TEST PITS- HAND EXCAVATION, NECESSARY BRACING AND DUE SAFETY PRECAUTIONS AND MOST VALUABLE SOIL CONDITIONS CAN BE STUDIED IN SITU
• • PILOT TUNNEL- FREQUENTLY CONSTRUCTED IN ADVANCED OF THE EXCAVATION
• WASH BORINGS- WASHING INSIDE A DRIVEN CASING AND RETAINING "SEDIMENT"
• • IN SITU TESTS - THE USE OF SMALL DIAMETER BORINGS AND DRILL HOLES IS OBVIOUS
• • STANDARD PENETRATION TEST- EQUIPPED WITH SMALL VERTICAL VANES
• DRY-SAMPLE BORING - WASHING INSIDE A DRIVEN CASING, SAMPLING TOOL USED AT A BOTTOM OF HOLE
• • ROCK CORE- REPRESENTS AN EXPENSIVE INVESTMENT
• UNDISTURBED SAMPLING- FORCING SAMPLING TOOL INTO CASED HOLE TO GET CONTINUOUS CORE SOIL
• CORE DRILLING - ROTATING POWER DRIVEN CORING TOOLS WITH DIAMOND, SHOT, OR STEEL CUTTERS
• • GEOPHYSICAL METHODS - A USEFUL AND ECONOMICAL SUPPLEMENT TO GEOLOGIC MAPPING, EXPLORATORY BORINGS, AND BACKHOE PITS
• CAISSONS, TRENCHING ADN TUNNELING - REGULAR CONSTRUCTION METHOD USED, WITH DUE SAFETY PRECAUTIONS
• METHODS OF DIRECT SUBSURFACE INVESTIGATION - HAND-AUGER BORING, TEST PITS, WASH BORINGS, DRY-SAMPLE BORING, UNDISTURBED SAMPLING, CORE DRILLING, (CAISSONS, TRENCHING AND TUNNELING )
• • SEISMIC METHOD - EXPLODING GUNPOWDER ON LAND OR ON THE SEA FLOOD TO CREATE ARTIFICIAL EARTHQUAKES
• PRELIMINARY INVESTIGATION- IS THE FIRST STEP IN EVALUATING THE LIKEHOOD OF SOIL OR GROUNDWATER CONTAMINATION TO BE PRESENT AT A SITE FROM CURRENT AND HISTORICAL USES
• • ARTIFICIAL GROUND MOTION - IS PRODUCED BY BLASTING
• • SEISMOGRAPHS - USED FOR RECORDING THE VIBRATIONS REACHING THE POINTS OF OBSERVATION
• SCOPE OF PRELIMINARY INVESTIGATION- WHEN A PROJECT IS FIRST CONTEMPLATED, THE SITE SHOULD ALWAYS BE EXAMINED IN A PRELIMINARY WAY, USING SUCH A TOPOGRAPHIC MAPS AS ARE AVAILABLE.
• • ELECTRICAL METHODS - PASSING A CURRENT THROUGH A SECTION OF THE EARTH'S CRUST
• REPORT OF PRELIMINARY INVESTIGATION- PREPARE A REPORT OF THE PRELIMINARY GEOLOGIC INVESTIGATION AND MAKE RECOMMENDATIONS ON THE NEED FOR FURTHER INVESTIGATION
• • ELECTRO LOGGING - USE OF RESISTIVITY METHODS IN WELLS OR DRILL HOLES
• • MAGNETIC METHODS - OLDEST OF ALL GEOPHYSICAL METHODS
• • MAGNETIC MERIDIAN - WHEN THE NEEDLE IS FREELY SUSPENDED ON VERTICAL AXIS, IT WILL COME TO REST IN A DIRECTION
• • MAGNETIC DIP - WHEN SUSPENDED ON A HORIZONTAL AXIS, IT WILL COME TO REST AT AN ANGLE HORIZONTAL
• REGIONAL GEOLOGY - IT IS THE GEOLOGICAL STUDY OF LARGE SCALE- REGIONS, IT ENCOMPASSES MULTIPLE GEOLOGICAL DISCIPLINES TO PIECE TOGETHER THE HISTORY OF AN AREA
• • MAGNETIC VARIOMETERS - MORE USUAL TYPES OF SUCH INSTRUMENTS, AND MAY BE THE VERTICAL TYPE
• PHOTO INTERPRETATION - CONCURRENT WITH THE REMARKABLE DEVELOPMENT OF AVIATION HAS GONE SIMILARLY SIGNIFICANT DEVELOPMENT IN THE USE OF AERIAL PHOTOGRAPHS AND OTHE REMOTHE IMAGERY FOR MAPPING AND SURVEY PURPOSES
• • GRAVITATIONAL METHODS - MADE WITH GRAVIMETERS OR GRAVITY METERS
• CORRELATION WITH GEOLOGY - IT CANNOT BE TOO STRONGLY EMPHASIZED THAT UNDERGROUND EXPLORATORY WORK MUST ALWAYS BE CONSIDERED SUPPLEMENTARY TO AND CONDITIONED BY PREVIOUS STUDIES OF LOCAL GEOLOGIC STRUCTURE. USING SATELLITE IMAGES
• • SURFICIAL DEPOSITS - ONE OF THE MOST EFFECTIVE APPLICATIONS OF GEOPHYSICAL METHODS, BOTH SEISMIC AND ELECTRICAL
• • GROUNDWATER - BOREHOLES
• GEOLOGIC MAPPING- THE MAPPING INVOLVES LITTLE MORE THAN ACCURATE OBSERVATION WITH THE UNAIDED EYE AND SIMPLE MEASUREMENTS WITH HAND INSTRUMENTS
• EXPLORATION TECHNIQUES - TO FUND OUT WHERE THE HIDDEN SURFACE OF ROCK LIES
• EXPLORATORY DRILLING IN ROCK- WHEN ROCK IS REACHED, EITHER IN A TEST PI OR IN TEST BORING, CHANGE IN METHOD IS NECESSARY IF THE ROCK IS TO BE PENETRATED
• • CONSTRUCTION OPERATIONS - The construction of a building or other structure.
• • ARCHIVAL RECORDS - AN ACCUMULATION OF HISTORICAL RECORDS
• LARGE DIAMETER EXPLORATORY HOLE- SUCH HOLES ARE EITHER ADVANCED BY PERCUSSIVE CHISELING AND CRUSHING OF ROCK OR DRILLED WITH MACHINES OF THE "CALYX" TYPE